According to a new study, long commutes aren't just annoying — they could also increase the risk of divorce.

The Local reports on a study of Swedish families that found a 40% increase in divorce risk for people with long commutes. There are a lot of possible explanations for this. Study author Erika Sandow offers one: "One of the long-term risks with commuting is that it can sustain gender-based stereotypes both at home and in the labour market." Swedish commuters tend to be men, meaning female partners may spend more time on chores and childcare while their dudes are on the train. Also, female partners of commuters may feel the need to get jobs closer to home or with shorter hours in order to take care of kids, meaning they may make less money or have less job satisfaction. Result: a commuting guy makes family life harder on women. Interestingly, swapping those roles may not solve the problem: earlier research has shown that women who commute have more stress and fewer feelings of success than male commuters.

Clearly commuting creates some problems that are gender-blind. It's annoying, especially if you have to do it by car, and a long trip home every night can put someone in a bad mood. It also takes time that could otherwise be spent with a partner or kids, and may put partners on drastically different schedules, which is hard on any union. It's tough to be the one waking up at 5 AM while your beloved sleeps — and tough to be the one who wishes he or she could stay in bed with you a little longer. Put all these together, and it's no wonder that commuting can strain marriages, especially at first — the effect of commuting on the divorce rate seems to dissipate somewhat after the first five years.

But it's also true that commuting seems to magnify some gender inequalities. The spouses of men who commute may have to work an even longer "second shift" and give up more professional opportunities. And yet when women commute, they still feel anxiety — perhaps over the expectation that they should be with their families and not on the road. The Swedish study shows that commuting has personal costs, and that a society where people live far away from their workplaces isn't necessarily ideal. But it's also a reminder that issues of work-life balance tend to affect women disproportionately — and they don't necessarily end when the workday is over.